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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
161

Modeling Channel Degradation at the Watershed Scale: A Comparison of GWLF, SWAT, and CONCEPTS

Staley, Nathan Andrew 05 January 2007 (has links)
In 2005 an assessment of existing Total Maximum Daily Load studies by the U.S. Environmental Protection Agency showed sediment as the fourth leading cause of water quality impairment. A source assessment is important in developing a successful TMDL. Past research efforts have focused on controlling erosion sources in agricultural and urban land areas. New research suggests major contributions to overall sediment loads may be due to stream channel degradation. Monitoring and modeling techniques to assess the contribution of channel sediment to overall sediment load are needed to determine the reductions necessary to meet water quality standards. This research focused on testing the ability of watershed and reach-scale models to predict stream channel degradation. Model predictions were compared to estimates developed from a system of erosion pins and scour chains. A 500-m experimental reach in Blacksburg, VA, USA, was selected as the focus of channel degradation monitoring and modeling efforts. A series of over 250 erosion pins and seven scour chains were installed systematically throughout the experimental reach. A monthly monitoring program measured channel degradation for the period from July 2005 - June 2006. Point data were interpolated across individual bank segments to produce an estimate of soil erosion volume. Measured soil bulk densities were then used to calculate the estimated mass loading to Stroubles Creek from channel degradation. Two watershed models and one reach-scale model were developed to predict sediment loading to the stream channel from channel degradation. The Generalized Watershed Loading Function (GWLF) was selected to represent watershed models with limited channel degradation process detail; the Soil and Water Assessment Tool (SWAT) represented the level of channel degradation detail seen in the majority of watershed models; and the CONservation Channel Evolution and Pollutant Transport System (CONCEPTS) reach-scale model was used to evaluate the effectiveness of a detailed process model. Monthly model predictions were compared to retreat rates measured using the erosion pin network. Sediment loading to the stream from bank retreat was estimated as 41 tonnes/yr, based on erosion pin measurements. GWLF, SWAT, and CONCEPTS predicted stream channel sediment contributions of 8 tonnes/yr, 1500 tonnes/yr and 4 tonnes/yr, respectively. Theil-Sen non-parametric simple linear regression was used to test agreement between monthly model predictions and erosion pin estimates. No significant agreement was found between any model predictions and measured retreat, using a conservative a-value of 0.2. GWLF model predictions underpredicted measured channel degradation, but most closely approximated observed data. This result is likely due to similarities in climate and watershed characteristics for the Stroubles Creek watershed and the Pennsylvania watershed used in the empirical model development. SWAT predicted retreat rates exceeded measured values by two orders of magnitude. This result is explained by the inability of SWAT to predict daily flow and sediment discharge. Highly sensitive channel degradation parameters and the lack of calibration data also contributed to SWAT simulation error. CONCEPTS simulation predicted monthly retreat rates slightly less than GWLF. The lack of agreement between CONCEPTS simulation and observed data was mainly the result of limited input data availability. SWAT daily discharge predictions were used as CONCEPTS input data and likely contributed to poor model agreement. Poor estimation of sensitive sediment input parameters may have also contributed to underpredictions by CONCEPTS. Results showed the potential of screening-level watershed models in channel degradation prediction and the importance of flow and sediment time series discharge data in detailed process-based simulation. The limited flexibility of the GWLF channel degradation algorithm makes it unsuitable for evaluating the effects of stream restoration. SWAT and CONCEPTS should only be used for evaluation if appropriate input data are available. Future research will focus on the development of a long-term flow and sediment monitoring data set. Few long-term data sets of this nature exist, making channel degradation modeling difficult. Development of long-term data will allow more accurate modeling and better assessment of channel restoration impacts on channel degradation. Further modeling with GWLF in geographic regions outside the Eastern United States is also needed to determine the scope of applicability of the GWLF channel degradation empirical relationship. Additional research should also focus on the significance of subaerial processes for watersheds of various sizes and on the development of algorithms to simulate these processes. / Master of Science
162

Application of children's reasoning skills: how children know a cat has life

盧立仁, Lo, Lap-yan. January 2002 (has links)
published_or_final_version / Psychology / Master / Master of Philosophy
163

Guided By the Mountains: Exploring the Efficacy of Traditional and Contemporary Dine' Governance

Lerma, Michael January 2010 (has links)
This research reviews Diné governance with an eye towards forecasting reform. What do traditional Diné institutions of governance offer to our understanding of the contemporary challenges faced by the Navajo Nation today and tomorrow? The research is part history, and part political science while pioneering applications of cutting edge research methods. Primary and secondary research will detail where Navajo Nation has been. Diné history is explored via creation stories, the Naachid systems, and the various contemporary councils. Unclear aspects of Diné history are illuminated by relying on oral accounts. Analysis pinpoints what is missing in governance today while questioning whether looking to the past alone will help make governance work better tomorrow. Sometimes adopting traditional Diné governance institutions is not feasible, not wanted, or not possible. New methodological territory offers insight when the past and the future do not work well together. The concept building method is utilized as a way of mitigating the loss that occurs when English words fail to capture the essence of Navajo language. Concepts organic to Navajo culture such as Naachid, Naat'aanii, War Naat'aanii, Peace Naat'aanii, etc, are turned to for assistance in dealing with contemporary issues. Navajo concepts are represented in three-level-view depictions. Three-level-view expressions require that concepts be observed on three-levels. Level one is the name. Under the name level are the set of necessary and sufficient conditions which must be present or you do not have an actual concept. Under each of the conditions are the data/observations which must be present in order to verify that the condition is present. Concept building displays where Navajo Nation has been in order to better understand where Navajo Nation needs to go. The visual presentation of traditional concepts of Diné governance makes them more understandable. Interestingly, when the concept building method is applied to post 1922 Diné governance, the true motives of the United States become obvious. A clearer path is presented toward incorporating chapter house government into national government. Developing contemporary concepts of Navajo governance based on traditional teachings equips us to deal with contemporary issues.
164

Quantifying small-scale geological uncertainty in reservoir models

Hastings, Jonathan James January 2000 (has links)
No description available.
165

Role of language in conceptual coordination

Laskowski, Cyprian Adam January 2011 (has links)
Although concepts are located within individual minds, while word forms are shared across entire language communities, words and concepts are normally deemed to be tightly bound. But in fact, at least to the extent that concepts vary, the relationship between words and concepts may not be as uniform or stable as is often assumed. Nevertheless, language may itself mediate that relationship, through its entrenchment and use. Psychologists have already investigated language use in referential communication, but they have yet to focus in detail on the role of language in conceptual coordination. One of the obstacles has been the theoretical and methodological challenges that arise from seriously abandoning conceptual universals. To that end, an experimental framework was developed based on sorting tasks in which participants freely partition a set of stimuli into categories and an objective measure for comparing two outputs. Four experiments were then conducted to investigate whether people were conceptually coordinated before, during and after linguistic interaction. Experiment 1 consisted of a cross-linguistic study looking at default coordination between native speakers. Participants both sorted items into groups and named them individually. There was a relatively high degree of categorisation agreement among speakers of the same language, but not nearly as high as for naming agreement. Experiments 2-4 inquired into conceptual coordination during or immediately after linguistic interaction. Experimental manipulations involved the form of language use (full dialogue or only category labels), as well as the type of feedback (category groupings, labels, both, or neither). In particular, Experiment 2 investigated the effects of categorising a set of objects together, with or without dialogue, on subsequent individual categorisation. The results were inconclusive and revealed specific methodological issues, but yielded interesting data and were encouraging for the general framework. Experiment 3 modified the designwhile testing and extending the same general hypotheses. Participants carried out a sequence of categorisation tasks in which they tried to coordinate their categories, followed by individual categorisation and similarity tasks. The availability of dialogue and feedback was manipulated in the interactive tasks. During interaction, they also received both kinds of feedback, except in the control condition. Pairs that could talk coordinated much better than the others, but feedback didn’t help. Experiment 4 looked into the effects of the four possibilities for feedback during a longer sequence of interactive tasks. In general, conceptual coordination was found to depend on grouping feedback only. However, by the end of the task, pairs who received both kinds of feedback did best. All three interactive experiments also measured lexical convergence between pairs. The results generally revealed a dissociation, with lexical alignment showingmore convergence and occurring under a wider variety of conditions. Togetherwith previous research, these findings showthat language can bring about conceptual coordination. However, it appears that the richer the form of language use, the more conceptual convergence occurs, and the closer it gets coupled with lexical convergence. The long-term effects, if any, are much weaker. These studies have implications for the general role of language in cognition and other important issues.
166

Visual conceptualizing in note review

Silliman, Benjamin January 2011 (has links)
Typescript (photocopy). / Digitized by Kansas Correctional Industries
167

Vygotsky's theory of scientific concepts and connectionist teaching in mathematics

Swanson, David January 2016 (has links)
This thesis can be described in various terms. It is a translation of Vygotsky's theory of scientific concepts, in reality a theory of development, into a theory of mathematics teaching and learning. It is a theorisation, and development, of connectionist pedagogy in mathematics (a relatively underdeveloped, yet exemplary, amalgam of various reform/progressive /meaningful approaches to teaching). And, it is an investigation of the elements and processes involved in mathematical concept development, and the mediating role which classroom tasks can play. Alongside this, these understandings are embedded within a wider understanding of society, schooling, mathematics and mathematics teaching which help explain the current dominant practice in the classroom, and in doing so add to the understandings already described. In sum, the thesis therefore represents the beginnings of a systematic Marxist perspective of mathematics education which can cohere analysis at the multiple levels of society, schooling, classroom teaching and learning, and individual concept development. As such it is also, as should always be the case with Marxist perspectives, a guide to action for critical mathematics educators. The thesis begins with context, motivation and strategy, an overview of relevant literature, and an explanation of the methodology and methods used within. The relationship between Vygotsky's theory of concept development and connectionist teaching is then outlined and developed. The wider societal perspective follows, with an emphasis on generalised commodity production as the key shaper of schools and classrooms. Both of these themes are then developed in relation to the example of vocational mathematics, both providing evidence of the existence and nature of scientific activity and concepts, and connecting their absence to the obstacles related in the previous section. The thesis continues by exploring a pedagogical development based on Vygotsky's theory, looking at the explicit problematising of generalisation, and analysing classroom dialogue in relation to this. In the other direction, a theoretical development is then made, following an illustration of the pedagogical and theoretical framework through the development of a particular concept. Finally, conclusions are drawn and future work outlined.
168

Dwelling in architecture: design for a house for two strangers.

Hanlen, M A Unknown Date (has links)
This exegesis seeks to explicate the current Masters project Dwelling in Architecture. The design component of the project a House for Two Strangers seeks to design a hypothetical domestic dwelling for two unrelated domestic strangers to inhabit. The site for the House for Two Strangers is located in Central Auckland City, on the corners of Beresford Square and Hopetoun Street.Dwelling in Architecture seeks to explore the possibility of engaging with notions of spatiality or temporality outside of homogeneous demarcation of space and time. Through the project a number of texts have been referred to in regard to questions concerning of the movement of subject-bodies through a spatio-temporal field. In conjunction to this questioning, has been a question concerning the locale of dwelling.
169

Teleosemantics, Externalism, and the Content of Theoretical Concepts

Burnston, Daniel C. 20 April 2009 (has links)
In several works, Ruth Millikan (1998a, 2000, 2006) has developed a ‘teleosemantic’ theory of concepts. Millikan’s theory has three explicit desiderata for concepts: wide scope, non-descriptionist content, and naturalism. I contend that Millikan’s theory cannot fulfill all of these desiderata simultaneously. Theoretical concepts, such as those of chemistry and physics, fall under Millikan’s intended scope, but I will argue that her theory cannot account for these concepts in a way that is compatible with both non-descriptionism and naturalism. In these cases, Millikan’s view is subject to the traditional ‘indeterminacy problem’ for teleosemantic theories. This leaves the content of theoretical concepts indeterminate between a descriptionist and non-descriptionist content. Furthermore, this problem cannot be overcome without giving up the naturalism desideratum. I suggest that the scope of Millikan’s theory should be limited. At best, the theory will be able to attribute naturalistic, non-descriptionist content to a smaller range of concepts.
170

Savoir kanak, savoir blanc les transferts de savoir entre tradition écrite et tradition orale à travers des textes d'élèves /

Silve, Nicole. Meirieu, Philippe January 1998 (has links)
Thèse doctorat : Sciences de l'éducation : Lyon 2 : 1998. / Titre provenant de l'écran-titre. Bibliogr.

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